A modern Japanese teacher who has Yamato Nadeshiko-like qualities and the sensibility of a woman from the countryside who receives looks from the nearby students. Even though she came to the city earlier than the main character, she still hasn't adjusted to the city life yet. She gets lost at large train stations, takes the stairs in tall buildings, and can't walk in a crowd of people. Because Komachi is from the countryside, she loves the outdoors, and although she hasn't been able to do so recently, her hobbies are hiking and camping.
She likes buying stuff and, since the city has a lot of stuff, can't help but stay.

Komachi was always helping around the house and busy with studying to be a teacher when she was a student so she hasn't had much of a chance to meet men. That's why she doesn't know much about how to deal with them. It seems like it will be a while before she will have sex with anyone but in reality she is very interested and is the one looking forward to it the most out of all the heroines.
Her distinguishing feature are her breasts which are over 100cm and reaches the level of being a weapon.